(Click image to enlarge) Photographed over Long Island, in The Bahamas © Dene Georgelin.
See this photo in the Cloud Gallery here.
The Cumulonimbus could never be called a refined cloud. It is the beast of the lower atmosphere: roaring with deafening thunder; spitting shards of lightning and hailstones; whipping up twisting tornadoes and spawning dramatic cloud features, such as the udder-shaped mammatus clouds, cigar-shaped roll clouds and, well, wall-shaped wall clouds. Sometimes, the Cumulonimbus also produces something called a ‘microburst’, which is best thought of as a cloud sneeze. Don’t be deceived by the ‘micro’ part: the sneeze of a Cumulonimbus is anything but restrained.
A microburst is a very localized column of air – up to 2.5 miles (4km) across – which shoots earthwards from the base of the cloud, spreading outwards with violent force upon reaching the ground. With gusting speeds of up to 150 mph, these winds can damage buildings, fell trees, and have been known to cause aviation crashes.
Much like human sneezes, microbursts can be either dry or wet. They do however last rather longer than ours: between 5 and 15 minutes. Along with chilly winds, the wet varieties produce sudden downpours. These can be quite heavy: enough to give you a cold, should you be in the firing line without the right clothing. Could the Cumulonimbus not muffle its vulgar microbursts? Presumably, no one has ever had the courage to try and teach this beast of the atmosphere any manners.
Current Cloud of the Month:
July 2010
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June 2010
May 2010
April 2010
March 2010
February 2010
January 2010
Cloud Reflections (December 09)
Numbers in the Clouds (November 09)
Sun Pillar (October 09)
Convection Clouds (September 09)
‘Pile d’Assiettes’ (August 09)
Cumulus congestus (July 09)
‘Asperatus’ (June 09)
Clouds at Night (May 09)
Sundogs (April 09)
Diamond Dust (March 09)
Cloud Streets (February 09)
Crepuscular Rays (Jan 09)
Valley Fog (December 08)
Cloud Shadows (November 08)
Contrails (October 08)
Mamma (September 08)
Kármán Vortex (August 08)
The Summertime Halo (July 08)
The Nor’west Arch (June 08)
Microbursts (May 08)
Irridescent Clouds (April 08)
Northern Lights – Aurora Borealis (March 08)
Ice halos (February 08)
Lightning (January 08)
Roll Cloud (December 07)
Banner Cloud (November 07)
Stratocumulus (October 07)
The Unclassified Cloud (September 07)
Alexander’s Dark Band (August 07)
Fumulus Snail (July 07)
Distrail (June 07)
Altocumulus undulatus (May 07)
Cumulonimbus capillatus (April 07)
Lacunosus (March 07)
Horseshoe Vortex Cloud (February 07)
Jet-Stream Cirrus (Janurary 07)
Altostratus/Altocumulus/Altowhateveritis (December 06)
Anti-Crepuscular Rays (November 06)
Stratocumulus (October 06)
Altocumulus (September ’06)
The Kelvin-Helmholtz Wave Cloud (August ’06)
The ‘Brocken Spectre’ (July ’06)
‘Whale’s Mouth’ (June ’06)
Noctilucent (May ’06)
Cirrus (April ’06)
Cap Cloud (March ’06)
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Cirrostratus (December ’05)
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Virga (October ’05)
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Altostratus (August ’05)
Cumulus (July ’05)
Mamma (June ’05)
Pileus (May ’05)
Lenticularis (April ’05)
Stratus (March ’05)
Cumulonimbus (February ’05)
Contrails (January ’05)
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